I can get the camera to go half-press, full-press, and un-press. The problem is that it won't stay in half-press after a full-press. What I need it to do is stay in the half press mode while I send multiple full-press pulses. That way I can get frames faster.
Is CHDK not mean to work like this ?
I don't think its really an issue with CHDK. Its more an issue with how the Ricoh CA-1 works. AFAIK, the CA-1 does not have a mode where you can hold the half press and just generate full presses. The nornal sequence is either a half-press followed but nothing ( cancel ) or a half-press followed by a full press (shoot).
Have you found anything to indicate that you can half-press the CA-1 switch, then full press, then release back to half-press ?
I suppose I could modify the USB remote code to support this. I don't think the CA-1 will actually do that but allowing multiple full-press operations with the half press held should be possible and would not interfere with normal CA-1 operation.
Does full-press always reset the state back to unpressed ?
That is my understanding. I have a CA-1 and that's the action I've seen on my scope. But I never tried letting up on the switch just enough to release the full press position while maintaining the half press. I'll give it a go and report back.
I'm thinking now that I might need to use this in conjunction with my own script to handle the pulses and shooting states properly.
Trying to catch CA-1 pulses in a script will be tricky but is possible. It would be much easier to just have your Arduino implement a "two press" switch though ...